Coinfection

CROI 2009: British Study Finds HIV-HCV Coinfected Patients Do Not Have Impaired CD4 Cell Recovery after Starting HAART

Studies to date have produced conflicting data on the question of whether HIV-HCV coinfected individuals experience slower or less extensive CD4 cell recovery after starting antiretroviral therapy (ART). 

As reported at the 16th Conference on Retroviruses and Opportunistic Infections (CROI 2009) last month in Montreal, Fiona Ewings of the Medical Research Council in London and colleagues analyzed how long it took for HIV monoinfected and HIV-HCV coinfected individuals to fall below 350 and 250 cells/mm3 after HIV seroconversion, as well as CD4 cell recovery after starting combination ART.

The study included 1622 participants in the U.K. Register of HIV Seroconverters. Within this cohort, 85% were persistently HCV negative, 11% were always HCV positive, and 4% seroconverted from HCV negative to positive during follow-up.

Compared with persistently HCV negative individuals, coinfected participants were more likely to be women (7% vs 26%) and injection drug users (IDUs)(1% vs 62%). Interestingly, 95% of HCV seroconverters were men who have sex with men, likely reflecting recent outbreaks of acute HCV infection among gay/bisexual men, even as rates of infection due to shared drug equipment have fallen.

Models were adjusted for sex, age at seroconversion, year of seroconversion, history of injection drug use, and response to antiretroviral therapy.

Results

  • Before starting combination ART, HIV-HCV coinfected individuals had a CD4 count 54 cells/mm3 lower than that of HIV monoinfected people, despite starting treatment at about the same time after HIV seroconversion (P = 0.03).
  • There was some evidence that CD4 cell count declined more rapidly in HIV-HCV coinfected patients compared with HIV monoinfected patients, but this did not reach statistical significance after adjusting for other factors.
  • Time to fall below 350 cells/mm3: 1.2 vs 2.4 years, respectively, adjusted hazard ratio [HR] 1.41 (P = 0.12).
  • Time to fall below 250 cells/mm3: 3.5 vs 5.6 years, respectively, adjusted HR 1.46 (P = 0.07).
  • Among 823 individuals (including 86 coinfected) with data available after ART initiation, there were no significant differences in time to HIV suppression or rate of CD4 cell recovery.
  • HIV-HCV coinfected patients spent a smaller percentage of time on NNRTI based regimens than HIV monoinfected individuals, a difference that was more pronounced among IDUs (24% vs 63%) compared with non-IDUs (41% vs 45%).
  • Coinfected individuals also spent more time off antiretroviral therapy, which again was more noticeable among IDUs (24% vs 10%) compared with non-IDUs (19% vs 15%).

In summary, the investigators concluded, compared to HIV monoinfected individuals, people with HIV-HCV coinfection initiated ART at lower CD4 cell counts, initiated ART at similar times after HIV seroconversion, may have faster CD4 cell count decline, though this was not statistically significant, and had similar responses to combination ART.

"[HIV-HCV] coinfected individuals may require frequent monitoring to ensure timely combination ART initiation, but appear to experience the same benefits of combination ART as those uninfected by HCV," they added.

3/03/09

Reference

F Ewings, A Copas, S Fidler, and others. HIV-infected Individuals Co-infected with HCV Appear to Have Faster CD4 Decline in the Absence of ART but Similar Response Once Combination ART Is Initiated. 16th Conference on Retroviruses and Opportunistic Infections (CROI 2009). Montreal, Canada. February 8-11, 2009. Abstract 851.